Can someone point me at a description of the difference between a 3G-A SDI signal and a 3G-B SDI signal.
I have a rack with a BlackMagic ATEM 2 M/E Production Studio 4K and a bank of 3 SWT Pro-HD monitors. The ATEM is set up to run 1080p59.94. The monitors show "No-sync" when fed from the Aux outputs of the ATEM.
If I insert a Decimator MD-HX between the Aux output and the monitor's SDI input, it shows the SDI input to the MD-HX running 3G-B 1920x1080p59.94. The SDI output of the MD-HX is switchable between 3G-A SDI and 3G-B SDI. Switching he output to 3G-A makes the signal appear on the monitor.
The problem does not appear if I run the ATEM at 720p59.94.
Wikipedia's article on SDI does not mention the A and B variants of SDI.